The present invention relates to absorbent particles which swell in the presence of aqueous solutions including saline and urine to many times their own weight. These absorbent materials are biodegradable and have absorptive properties equal to or higher than those of present superabsorbers.
Biodegradability of disposable products is no longer a preferred option; it has become a necessity. As the number of disposables in society has grown, the land fills and others methods of treatment for these disposables have been strained to the limits. Plastics are just one form of the problem of disposables while absorbent materials such as polyacrylates which are commonly used, e.g., in disposable diapers, have degradation times in the thousands of years. While the superabsorber such as the polyacrylates have advantages because of their high absorptive capabilities so that less is needed to attract a large amount of liquid, the non-biodegradability of these products makes them unacceptable if alternatives can be achieved.
Particulate superabsorbers can be used either in lose or packed form or else can be dispersed among fibers, e.g., cellulose fluff, to act as part of a liquid absorption system. However, if they are used in a packed form, the gel blocking problem must be ameliorated in order to provide optimum action.
Accordingly, an object of the invention is to provide a biodegradable superabsorbent particle which is competitive with the polyacrylate superabsorbers in terms of uptake for aqueous solutions and saline.
Another object of the invention is to provide methods of making biodegradable superabsorbers which use inexpensive material and are rapid.
A further objection of the invention is to provide a superabsorber which can act as a delivery system for a variety of materials, e.g., enzymes.
These and other objects and features of the invention will be apparent from the following description.